Narcolepsy is a disorder of excessive daytime sleepiness, characterized by sudden and uncontrollable attacks of deep sleep.

Restless Legs Syndrome and Periodic Limb Movement Disorder are discomforts or twitching in the legs that occurs after going to bed causing sleep disruption. The restless legs syndrome can be seen in up to 30 percent of patients older than age 65.

Parasomnias are disruptive sleep-related behaviors that range from night terrors to sleep walking.

Insomnia is the chronic inability to fall asleep or remain asleep for an adequate length of time.